These 80-year-olds have the memory of 50-year-olds. Scientists finally know why

• SuperAgers are people over 80 whose memory performs as well as someone 30 years younger, showing that exceptional cognitive health can last a lifetime.
• They tend to be highly social, maintaining strong relationships and active lifestyles, and their brains appear to resist the buildup of Alzheimer's-related plaques and tangles that often cause memory loss.
• Ongoing research is revealing powerful insights that could help scientists develop new ways to delay or even prevent dementia linked to neurodegenerative diseases such as Alzheimer's and frontotemporal degeneration.

For the past 25 years, researchers at Northwestern Medicine have been examining people aged 80 and older, known as "SuperAgers," to uncover why their minds stay so sharp.

These remarkable individuals perform on memory tests as well as people 30 years younger, challenging the long-held idea that mental decline is an unavoidable part of getting older.

Throughout the decades of research, scientists have noticed that SuperAgers often share certain lifestyle and personality traits, such as being highly social and outgoing. However, according to Dr. Sandra Weintraub, professor of psychiatry, behavioral sciences, and neurology at Northwestern University Feinberg School of Medicine, the most astonishing discoveries have come from looking directly at their brains. "It's really what we've found in their brains that's been so earth-shattering for us," she said.

By pinpointing the biological and behavioral features linked to SuperAging, the researchers aim to develop new ways to strengthen cognitive resilience and slow or prevent Alzheimer's disease and other types of dementia.

"Our findings show that exceptional memory in old age is not only possible but is linked to a distinct neurobiological profile. This opens the door to new interventions aimed at preserving brain health well into the later decades of life," said Weintraub, corresponding author of a new paper summarizing the findings.

The paper was published as a perspective article in Alzheimer's & Dementia: The Journal of the Alzheimer's Association, published in a special issue marking both the 40th anniversary of the National Institute on Aging's Alzheimer's Disease Centers Program and the 25th anniversary of the National Alzheimer Coordinating Center.

SuperAger brains are resilient, resistant

The term "SuperAger" was first introduced by Dr. M. Marsel Mesulam, founder of the Mesulam Center for Cognitive Neurology and Alzheimer's Disease at Northwestern, in the late 1990s.

Since 2000, 290 SuperAgers have participated in the study, and researchers have examined 77 donated SuperAger brains after death. Some of these brains contained amyloid and tau proteins (also known as plaques and tangles), which are key hallmarks of Alzheimer's disease, while others showed no buildup at all.

"What we realized is there are two mechanisms that lead someone to become a SuperAger," Weintraub said. "One is resistance: they don't make the plaques and tangles. Two is resilience: they make them, but they don't do anything to their brains."

Other key findings:

• Exceptional memory performance: SuperAgers score at least 9 out of 15 on a delayed word recall test -- on par with individuals in their 50s and 60s.
• Youthful brain structure: Unlike typically aging brains, SuperAgers show no significant thinning of their cortex -- the outer layer of the brain -- and even have a thicker anterior cingulate cortex than younger adults. This crucial region of the brain plays a significant role in integrating information related to decision-making, emotion and motivation.
• Unique cellular traits: SuperAgers have more von economo neurons, which are specialized cells linked to social behavior, and larger entorhinal neurons, which are critical for memory, than their typically aging peers.
• Sociability as a common trait: Despite having diverse lifestyles and varying approaches to exercise, SuperAgers tend to be highly social and report strong interpersonal relationships.

'Brain donation can offer scientific immortality'

At the Mesulam Center, SuperAgers are evaluated annually and may choose to donate their brains for post-mortem evaluation by Northwestern scientists.

"Many of the findings from this paper stem from the examination of brain specimens of generous, dedicated SuperAgers who were followed for decades," said co-author Dr. Tamar Gefen, associate professor of psychiatry and behavioral sciences at Feinberg, director of Feinberg's Laboratory for Translational Neuropsychology and a neuropsychologist at the Mesulam Center. "I am constantly amazed by how brain donation can enable discovery long after death, offering a kind of scientific immortality."

The perspective piece is titled, "The First 25 Years of the Northwestern SuperAging Program." Other Northwestern authors include Dr. Mesulam and Changiz Geula, research professor of cell and developmental biology and neuroscience at Feinberg and a member of the Mesulam Center.